This invention relates to a golf ball having a cover, and in particular to a golf ball having a polyurethane cover.
Ionomer resins and polyurethanes have been used as the base resins constituting the covers of golf balls. Although golf balls having a cover made of an ionomer resin are superior in rebound characteristics, durability, processability, and the like and thus have been widely used, various problems associated with these balls have been pointed out that the golf balls are inferior in hitting feeling, insufficient in spin performance, inferior in controllability, and the like due to the high stiffness and hardness of these balls. To solve the problems, Japanese Patent No. 2709950, for example, discloses a method of improving the hitting feeling and spin performance by blending hard and soft ionomer resins, but blending of a soft ionomer resin is inevitably accompanied with decrease in rebound characteristics and abrasion resistance of the resulting golf ball. On the other hand, polyurethanes have been used as the base resin constituting the cover, because the resins provide golf balls more improved in hitting feeling and spin performance than ionomer resins. However, the rebound characteristics and abrasion resistance of the covers using polyurethanes are still at an unsatisfactory level. To solve these problems, Japanese Unexamined Patent Publication No. 2002-360740 discloses, for example, a golf ball using a mixture of a thermoplastic polyurethane elastomer and a thermoplastic polyamide elastomer as the base resin constituting the cover.